Expression of E-cadherin in squamous cell carcinomas of the supraglottic larynx with correlations to clinicopathological features

Preliminary Correlation of the Immunoexpression of Cathepsin B and E-Cadherin Proteins in Vocal Fold Leukoplakia

OBJECTIVES

Early identification of vocal fold leukoplakia (VFL), which has a risk of progressing to malignant transformation, remains a controversial topic. The identification of biological markers for diagnosing these lesions would lead to a more effective treatment. We aimed to analyze the immunoexpression of cathepsin B and E-cadherin in VFL and correlate it with clinical and epidemiological data and disease prognosis.

METHODS

Thirty-two patients with VFL treated with microsurgery were retrospectively evaluated. The patients were distributed according to the histological results into Group A (low grade) and Group B (high grade). The expression of markers was quantitatively determined as per their staining intensity and tissue distribution using ImageLab. The index of expression (IE) of each marker was correlated with tobacco and alcohol consumption, signs of laryngopharyngeal reflux, and local recurrence of the lesion.

RESULTS

The correlation between the IE of markers and variables within the two groups (A and B) demonstrated that patients in Group B with local recurrence had a higher IE of cathepsin B. When all patients (A + B) were included, the same analysis demonstrated that the IE of cathepsin B was higher among smokers and patients who did not show signs of reflux and that the IE of E-cadherin was higher only in patients with recurrence.

CONCLUSION

Patients with moderate to severe dysplasia and carcinoma in situ who smoked as well as had a high IE of cathepsin B were more prone to local recurrence. Regardless of the type of histological lesion, patients with signs of laryngopharyngeal reflux had a lower IE of cathepsin B. The IE of E-cadherin was higher among patients with VFL who relapsed after initial treatment.

Overview on Molecular Biomarkers for Laryngeal Cancer: Looking for New Answers to an Old Problem

Laryngeal squamous cell cancer (LSCC) accounts for almost 25-30% of all head and neck squamous cell cancers and is clustered according to the affected districts, as this determines distinct tendency to recur and metastasize. A major role for numerous genetic alterations in driving the onset and progression of this neoplasm is emerging. However, major efforts are still required for the identification of molecular markers useful for both early diagnosis and prognostic definition of LSCC that is still characterized by significant morbidity and mortality. Non-coding RNAs appear the most promising as they circulate in all the biological fluids allowing liquid biopsy determination, as well as due to their quick and characteristic modulation useful for non-invasive detection and monitoring of cancer. Other critical aspects are related to recent progress in circulating tumor cells and DNA detection, in metastatic status and chemo-refractoriness prediction, and in the functional interaction of LSCC with chronic inflammation and innate immunity. We review all these aspects taking into account the progress of the technologies in the field of next generation sequencing.

The Role of E-Cadherin as a Prognostic Biomarker in Head and Neck Squamous Carcinoma: A Systematic Review and Meta-Analysis

PURPOSE

In this study, we systematically investigated and analyzed articles focusing on the prognostic value of E-cadherin (E-cad) in human head and neck squamous cell carcinoma (HNSCC).

METHODS

Searching through the different databases, the studies examining the associations between E-cad and HNSCC prognosis were identified. Outcomes such as disease-specific survival and overall survival were considered acceptable. Hazard ratio (HR) with 95% confidence interval (CI) was used to demonstrate prognostic value.

RESULTS

A total of 40 studies were systematically analyzed, and finally, 1939 subjects were included in our meta-analysis. Our findings showed that significant aberrant expression of E-cad was associated with poor survival. However, some studies showed increased expression of E-cad in metastatic lesions was associated with poor prognosis. Alteration in location of E-cad expression also showed significant association with cancer survival, i.e., increased cytoplasmic E-cad. We conducted a meta-analysis on the eligible articles using a random effect model because of moderate heterogeneity. Strong association between aberrant expression of E-cad and poor survival was demonstrated (pooled HR = 2.28; 95% CI 1.78-2.91).

CONCLUSIONS

Aberrant expression of E-cad may be a promising prognostic signature for HNSCC, especially when it is used with other prognostic markers.

MiR-196b affects the progression and prognosis of human LSCC through targeting PCDH-17

OBJECTIVE

To explore the effect of miR-196bon the biological features of human laryngeal squamous cell carcinoma (LSCC) through targeting PCDH-17.

METHODS

miR-196b and PCDH-17 expressions were determined in tissues, and the targeting relation of miR-196b and PCDH-17 was verified through dual-luciferase reporter system. In vitro, Hep-2 cells were divided into the Control, miR-196b inhibitors, miR-NC, PCDH-17, and miR-196b mimics+PCDH-17 groups. The miR-196b and PCDH-17 expressions were determined by qRT-PCR or/and Western blot, and the biological features by MTT, Annexin V-FITC/PI, wound-healing and Transwell assays.

RESULTS

MiR-196b was found to be up-regulated, while PCDH-17 was down-regulated in a negative correlation in LSCC patients, which was related to histological grade and TNM stage. And low expression of miR-196b and high expression of PCDH-17 contributed to an increase in the 5-year-survival rate of LSCC patients. Besides, miR-196b directly targeted PCDH-17, while miR-196b inhibitors could up-regulate the PCDH-17 in Hep-2 cells. Moreover, miR-196b inhibitors and PCDH-17 curbed Hep-2 cell proliferation but facilitated the apoptosis, with decreases in cell invasion and migration. In addition, no statistical significance was found in cell proliferation, apoptosis, invasion and migration between Control group and miR-196b mimics+PCDH-17 group.

CONCLUSION

LSCC patients exhibited the up-regulated miR-196b and down-regulated PCDH-17, which are correlated with the major clinical features and prognosis. Inhibiting miR-196b may suppress proliferation, migration and invasion abilities, and promote apoptosis of Hep-2 cells via targeting PCDH-17.

Role of E-cadherin and cyclin D1 as predictive markers of aggression and clonal expansion in head and neck squamous cell carcinoma

Objectives

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. Inconsistency in various histopathologic features for predicting nodal metastasis and overall prognosis and a better understanding of molecular mechanisms of tumourigenesis have shifted the focus to a search for more definitive predictive markers. To identify the role of two immunohistochemical (IHC) markers, E-cadherin and cyclin D1, as predictive markers of aggressiveness in HNSCC and to assess clonal expansion of tumour cells.

Materials and Methods

A total of 66 cases of HNSCC with neck node dissection were studied. IHC was performed on primary tumour sections and lymph nodes showing metastatic deposits. Histopathological parameters such as tumour grade and TNM stage together with nodal status were compared according to expression of the two markers. Fischer's chi-square test was used to assess the correlation between the two markers and histopathological parameters.

Results

Out of 66 cases studied, 37 showed LN metastasis. Most of the patients were male, and the most common tumour site was buccal mucosa. We found a significant association between loss of E-cadherin and node metastasis (P<0.001) and higher TNM stage (P<0.001). Cyclin D1 overexpression was significantly associated with only nodal metastasis (P=0.007). No significant association with tumour grade was found for either marker. The subgroup of E-cadherin loss with cyclin D1 overexpression was associated with the maximum incidence of nodal metastasis and higher TNM stage, highlighting the importance of using a combination of these two markers. A significant association was noted between the expression of markers at the primary site and at nodal deposits, indicating clonal expansion.

Conclusion

A combination of the two markers E-cadherin and cyclin D1 can predict prognosis in HNSCC, although tumour heterogeneity may affect this association in some cases.

The role of E-cadherin and β-catenin in laryngeal cancer

Epithelial cadherins with catenins form the E-cadherin-catenin complex that acts on cell-to-cell adhesion. The loss of these complex lead to the reduction or absence of epithelial cadherin expression in the cell membrane, cytoplasmic accumulation of β-catenin and its translocation to the nucleus, contributing to carcinogenic events. The objective of this study was to evaluate the expression of epithelial cadherin and β-catenin in patients with laryngeal tumor. A retrospective study of 52 patients with glottic or supraglottic squamous cell carcinoma was conducted and evaluated according to the tumor site, histological differentiation, TNM stage, survival analysis and compared with the immunohistochemical expression of epithelial cadherin and β-catenin. We observed statistically significant association between the epithelial cadherin expression reduction and supraglottic localization of the lesion, the presence of cervical metastasis, poorly differentiated tumors and locally advanced tumors when in glottic topography. Related to the expression of β-catenin, statistical significance was also found to the presence of cervical metastasis and tumor of low differentiation with the decreased expression of this marker. Regarding survival analysis, the low expression of β-catenin is related to worse overall survival and the reduction of expression of both markers to worse disease-free survival. We concluded that the reduction in expression of the markers studied leads to a prognostic impact as they are related to tumors with greater local aggressiveness and presence of cervical metastasis.

Prognostic significance of E-cadherin and β-catenin expression in HPV-negative oropharyngeal squamous cell carcinomas

BACKGROUND

The purpose of this work was to investigate the prognostic significance of E-cadherin and β-catenin expression in surgically treated human papillomavirus (HPV)-negative patients with oropharyngeal squamous cell carcinoma (SCC).

METHODS

Consecutive patients with oropharyngeal SCC who underwent surgical treatment between 1990 and 2009 were retrospectively collected. Immunohistochemical analysis of E-cadherin and β-catenin expression was performed on tissue microarrays.

RESULTS

E-cadherin and β-catenin expression was evaluable in 232 cases. Low membranous E-cadherin, low membranous β-catenin expression, and nuclear β-catenin expression were associated with a poorer disease-specific and overall survival, although the differences were only significant for β-catenin membranous expression (P = .024 and P = .016, respectively). In multivariate analysis, nodal metastasis and low membranous β-catenin expression were significant independent predictors of reduced disease-specific and overall survival.

CONCLUSION

Low membranous β-catenin expression is a significant independent predictor of both reduced disease-specific and overall survival in patients with HPV-negative oropharyngeal SCC.

Ki-67 is overexpressed in human laryngeal carcinoma and contributes to the proliferation of HEp2 cells

Ki-67 is one of the most useful markers to evaluate cell proliferative activity and has been widely used in tumor treatment and research. However, its role in human laryngeal carcinoma remains poorly defined. The aim of the present study was to investigate the expression of Ki-67 in human laryngeal squamous carcinoma and the effect of Ki-67 gene silencing by small interfering (si)RNA on the proliferation of human laryngocarcinoma HEp2 cells. Immunohistochemistry and reverse transcription-quantitative polymerase chain reaction were performed to examine the expression of Ki-67 in human laryngeal squamous carcinoma tissues and adjacent non-cancer tissues from 50 patients with laryngeal squamous carcinoma. RNA interference was used to knock down the expression of Ki-67 in the HEp2 cell line, and the proliferation of the treated cells was observed in vitro. Western blot analysis was used to determine the expression levels of epidermal growth factor receptor (EGFR) and E-cadherin in the treated cells. The expression of Ki-67 in the laryngeal squamous carcinoma tissues was significantly higher than that of the adjacent non-tumor tissues (P=0.028). The high expression of Ki-67 in cancer was significantly correlated with cervical lymph node metastasis and clinical outcomes (all P<0.001). The silencing of Ki-67 resulted in the inhibition of proliferation of the HEp2 human laryngocarcinoma cells (P<0.001). In addition, compared with the control group, the expression levels of EGFR and E-cadherin in the Ki-67 siRNA-treated cells were significantly decreased (P<0.001) and increased (P<0.001), respectively. These results suggested that Ki-67 is important in regulating the proliferation of human laryngocarcinoma HEp2 cells and that the mechanism may at least partially be associated with the upregulation of EGFR and the downregulation of E-cadherin. Overall, Ki-67 can be used as an important indicator for judging clinical progress and estimating prognosis in human laryngeal squamous carcinoma.

Basement membrane protein ladinin-1 and the MIF-CD44-β1 integrin signaling axis are implicated in laryngeal cancer metastasis

Laryngeal squamous cell carcinoma (LSCC) is the most common form of malignant disease in the head and neck region characterized by frequent occurrence of metastases in the neck lymph nodes early in the disease onset. In the presented study, we performed quantitative proteomic profiling of patient-matched primary tumor and adjacent non-tumorous tissues derived from metastatic LSCC as to identify new protein candidates with potential diagnostic and therapeutic significance. Obtained results revealed for the first time involvement of the basement membrane protein ladinin-1 in laryngeal cancer metastases. Alterations in the cellular microenvironment that propel metastatic events in laryngeal cancer include activation of MIF-CD44-β1 integrin signal transduction pathway and induction of downstream signaling mediated by NF-κB and Src tyrosine kinase, which ultimately impinge on cytoskeletal dynamics and architecture resulting in increased cellular motility and invasiveness. In this context, particularly interesting finding is upregulation of several actin-binding proteins novel to laryngeal cancer pathogenesis including coronin-1C and plastin-2, whose functional significance in laryngeal carcinogenesis has yet to be established. We also detected for the first time a complete loss of afamin in metastatic laryngeal cancer tissues, which warrants further studies into its use as a possible marker for monitoring disease progression and/or treatment outcome.

Decreased E-Cadherin but not β-Catenin Expression is Associated with Vascular Invasion and Decreased Survival in Head and Neck Squamous Carcinomas

OBJECTIVES: We wished to correlate the expression of E-cadherin and β-catenin in squamous carcinomas of the head and neck to outcome and other clinicopathologic variables.

STUDY DESIGN AND SETTING: This retrospective study was carried out in a tertiary care setting. The tumors of 45 patients who had their head and neck squamous carcinoma primarily treated by resection were evaluated immunohistochemically with antibodies to E-cadherin and β-catenin. Thirty-two tumors arose in the oral cavity, 9 tumors originated in the larynx, and 4 tumors began in the hypopharynx. Patient outcome and the clinicopathologic variables of tumor site, tumor stage, cervical lymph node status, tumor differentiation, perineural invasion, and vascular invasion were correlated to immunohistochemical expression of E-cadherin and β-catenin.

RESULTS: Low expression of E-cadherin in the tumors was significantly associated with decreased overall survival ( P = 0.004), disease-free survival ( P = 0.007), and vascular invasion ( P = 0.02) but not with other clinicopathologic variables. β-catenin expression was not significantly associated with any of the studied clinicopathologic variables.

CONCLUSION: Decreased E-cadherin but not β-catenin expression is associated with decreased survival in patients with head and neck squamous carcinomas.

SIGNIFICANCE: Detection of loss of E-cadherin expression may help predict which patients with head and neck squamous cell carcinoma will experience a worse outcome compared to patients whose tumors have not lost this tumor suppressor.

EBM rating: C-4

Predictive value of E-cadherin and Ep-CAM in cervical lymph node metastasis of supraglottic larynx carcinoma

OBJECTIVE

To evaluate the value of E-cadherin and epithelial cell adhesion molecule (Ep-CAM) expression in laryngeal biopsy materials for predicting cervical lymph node metastasis in patients with supraglottic laryngeal carcinoma.

METHODS

All patients participating in the study were selected from among the surgically treated patients at the department of Otolaryngology, Head and Neck Surgery, Erciyes University School of Medicine between 1991 and 2005. The study consisted of thirty patients who had pathologically metastatic lymph nodes (pN+ group) and 30 age-, sex-, T value- and differentiation matched patients without pathologically metastatic lymph nodes (pN0 group). Immunohistochemical studies were performed with E-cadherin and Ep-CAM antibodies on representative tumor sections collected from paraffin sections of laryngeal biopsy materials. The expression of E-cadherin and Ep-CAM was compared between the pN0 and pN+ groups. The association between immunostaining of E-cadherin and Ep-CAM was also evaluated.

RESULTS

There was no significant difference between the two groups in terms of E-cadherin and Ep-CAM expression. There was also a very poor agreement between the expression of E-cadherin and Ep-CAM.

CONCLUSION

Multi-institutional and multidisciplinary immunohistochemical studies conducted with standardized methodology and also with more patient participation may help to obtain more specific results.

p63 and E-cadherin Expression in Canine Oral Squamous Cell Carcinoma

The expression of p63 and E-cadherin was studied in 22 oral squamous cell carcinomas in the dog according to immunohistochemical techniques. The association between these markers and clinicopathologic parameters was assessed. All tumor cells studied showed enhanced p63 expression. Regarding E-cadherin expression, 17 of 22 cases (77.3%) showed decreased immunoreactivity, and in 13 of 22 cases (59.1%), its expression was cytoplasmic. Neither p63 nor E-cadherin expression patterns were associated with tumor size, bone invasion, or lymph node metastasis. p63 score was related to proliferating cell nuclear antigen proliferative index (P = .020). A statistically significant correlation between the expression patterns of these 2 markers was noted (P = .026). Furthermore, they were related with tumor grade. An atypical p63 labeling and a cytoplasmic E-cadherin staining were statistically related with a higher tumor grade (P = .022 and P = .017, respectively). These findings suggest that changes in p63 and E-cadherin expression are frequent events in oral squamous cell carcinoma in dogs.

Study of β-catenin, E-cadherin and vimentin in oral squamous cell carcinoma with and without lymph node metastases

Abstract

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6506095201182002.

Immunohistochemical markers of distant metastasis in laryngeal and hypopharyngeal squamous cell carcinomas

Metastasis remains a major cause of mortality in head and neck squamous cell carcinoma (HNSCC). Current clinicopathological features have shown limited predictability for the risk of distant metastasis in individual patients, and therefore more accurate and reliable markers are needed. The aim of this study was to investigate the ability of various molecular markers present in primary tumors to predict the risk of developing distant metastasis. Restrictive clinical criteria were applied for patient selection in order to carry out a case-control study with comparable clinical features on a group-wide basis and a similar risk of metastasis. All patients were surgically treated (with postoperative radiotherapy when appropriate) and classified as stage IV disease. Immunohistochemical analysis was performed for a panel of proteins known to participate in cellular processes relevant to metastatic dissemination (E-cadherin, annexin A2, cortactin, FAK, EGFR, p53, and p-AKT). Results showed that the loss of E-cadherin expression was significantly correlated with the risk of distant metastasis (P = 0.002; log-rank test), while the loss of annexin A2 expression was nearly statistically significant (P = 0.06). None of the other protein markers assessed were associated with the development of distant metastasis. Therefore, according to our data the loss of epithelial adhesion seems to play a central role in the development of metastasis in HNSCC, and more importantly, immunohistochemical assessment of key proteins involved in cell adhesion regulation, such as E-cadherin could represent a useful tool to evaluate easily and routinely the metastatic potential of these carcinomas.

Prognostic factors and biomarkers of penile carcinoma

Penile squamous cell carcinoma (SCC) is a rare malignancy with highest incidence in underdeveloped and developing countries. Oncogenic human papilloma virus (HPV) DNA, mainly types 16 and 18, are found in ∼ 100% of patients with uterine cervix carcinoma. The incidence of this virus in SCC and its variations range from 30.5 to 80%. Despite controversies, contrary to the cervical carcinoma, in the carcinogenesis and disease progression of SCC, HPV-dependent and HPV-independent tumors need to be considered. Lymphadenectomies continue to be the gold standard treatment of lymph node metastases. Undesirable accuracy on staging system methods and high rates of lymphadenectomy complications are the principal objections to these surgical procedures; therefore, the main issue in patients with SCC is to know who should or should not undergo lymphadenectomy. The search for primary tumor anatomopathological and biomarker risk factors for lymph node metastases, such as has occurred in other tumors, may be an important tool to select lymphadenectomies candidates better. Histological subtypes, tumor grade, growth pattern, tumor thickness, lymphatic embolization by neoplasic cells and depth of infiltration have been reported as important prognostic factors for lymph node metastases. In our series, lymphatic vascular permeation, palpable lymph node after primary tumor control (cN stage), pattern of invasion, p53 and PCNA immunoreactivity are independent lymph node metastases risk factors in the multivariate model. It is strongly recommended that patients be concentrated in specialized centers or cancer hospitals and multi-centric prospective studies carried out on tumor markers in this rare disease, in order to stage better lymph node disease and avoid unnecessary surgeries with high morbidity rates.

Epigenetic dysregulation in laryngeal squamous cell carcinoma

Laryngeal carcinoma is a common head and neck cancer with poor prognosis. Patients with laryngeal carcinoma usually present late leading to the reduced treatment efficacy and high rate of recurrence. Despite the advance in the use of molecular markers for monitoring human cancers in the past decades, there are still no reliable markers for use to screen laryngeal carcinoma and follow the patients after treatment. Epigenetics emerged as an important field in understanding the biology of the human malignancies. Epigenetic alterations refer to the dysregulation of gene, which do not involve the alterations of the DNA sequence. Major epigenetic changes including methylation imbalance, histone modification, and small RNA dysregulation could play a role in the development of human malignancies. Global epigenetic change is now regarded as a molecular signature of cancer. The characteristics and behavior of a cancer could be predicted based on the specific epigenetic pattern. We here provide a review on the understanding of epigenetic dysregulation in laryngeal carcinoma. Further knowledge on the initiation and progression of laryngeal carcinoma at epigenetic level could promote the translation of the knowledge to clinical use.

Is E-cadherin immunoexpression a prognostic factor for head and neck squamous cell carcinoma (HNSCC)? A systematic review and meta-analysis

We summarized existing evidence about whether the aberrant E-cadherin expression is a prognostic factor for patients with HNSCC. Identifying relevant articles, filtrating studies and extracting data were independently conducted by two reviewers. The quality of eligible studies was assessed according to systematic score criteria. Associations between aberrant E-cadherin expression and overall survival (OS) or disease-free survival (DFS) were summarized by hazard ratio (HR) estimates. Random or fixed effects models were used to investigate the effect of E-cadherin across the studies. According to the multivariate and univariate analyses, the meta-analysis of the included studies gave a statistically significant pooled HR for OS in HNSCC [the pooled HR=2.533; 95% confidence interval (CI)=1.971-3.254]. In addition, the subgroup analyses showed that the pooled HR of each subgroup also exhibited statistical significance according to the subpopulations (Asian and other subpopulations), treatments (surgery and other treatments), locations of primary tumors (oral cavity and other subsites), and data sources of HR (reported and estimated HR). Similar to the results of OS, the analysis of four included trials showed that the aberrant E-cadherin expression could predict low DFS. Meanwhile, a cumulative meta-analysis showed that the pooled HR became statistically significant. However, a meta-regression analysis showed that the OS was not statistically significant with the cutoff values of the included studies. Our study gives an important piece of evidence that aberrant E-cadherin expression was associated with a poor prognosis in patients with HNSCC.

The cadherin-catenin complex in laryngeal squamous cell carcinoma

Abnormal Wnt signaling and impaired cell–cell adhesion due to abnormal E-cadherin and β-catenin function have been implicated in many cancers, but have not been fully explored in laryngeal squamous cell carcinoma. In this study, β-catenin cellular location and E-cadherin expression levels were analyzed in 16 laryngeal squamous cell carcinomas (LSCCs) (9 glottic and 7 supraglottic) and 11 samples of non-tumoral inflammatory larynx tissue, using immunohistochemical methods. All non-tumoral tissues showed equally strong membranous expression of β-catenin, while cytoplasmic expression was found in only 3 of the 11 samples. By contrast, whereas 8/9 glottic LSCCs exhibited only membranous expression of β-catenin, 6/7 supraglottic LSCCs displayed both membranous and cytoplasmic expression (p = 0.003). Strong E-cadherin staining was observed in 9/11 non-tumoral tissues and 7/9 glottic LSCCs, whereas 4/7 supraglottic LSCCs exhibited weak expression. Reduced membrane expression of E-cadherin and cytoplasmic retention of β-catenin in supraglottic LSCC seems to be related with more aggressive biological behavior which has been described in clinical studies. Further research is required to clarify the involvement of β-catenin in the mechanism associated with malignant transformation in laryngeal tissues.

Genetic model of transformation and neoplastic progression in laryngeal epithelium

BACKGROUND

The aim of this study was to analyze genetic alterations in the transformation-progression model of laryngeal tumors.

METHODS

Copy number changes of 37 genes were analyzed by multiple ligation-dependent probe amplification (MLPA) in 94 tissue samples.

RESULTS

In the smoker normal mucosa group TP53 loss was predominant, whereas in the precursor lesions CDKN2A loss and CDKN2D gain were most frequent. Precursor lesions with progression presented CTNNB1 loss. In the carcinoma group the most common changes were CDKN2A, MLH1, CTNNB1, and CASP6 losses and RECQL4, CCND1, and EMS1 gains. Positive lymph node primary tumors were related to TP53, IL1A, and RB1 losses and STK11 gain. The lymph node metastases differed from their corresponding primary tumor in LMNA, RECQL4, and IGF1R losses, and N33 and CDKN2D gains.

CONCLUSIONS

Genetic changes and new key genes were found to be associated with specific steps. We included new steps, not presented in the classic models: normal mucosa tobacco exposed, positive lymph node primary tumor, and corresponding lymph node metastases.

The cadherin-catenin complex in nasopharyngeal carcinoma

Abnormal Wnt signaling and impaired cell–cell adhesion due to abnormal E-cadherin and β-catenin function have been implicated in many cancers, but have not been fully explored in nasopharyngeal carcinoma. The aim of this study was to analyze β-Catenin cellular location and E-cadherin expression levels in nasopharyngeal carcinoma. E-cadherin expression levels were also correlated with clinical data and underlying pathology. β-Catenin and E-cadherin expression were examined in 18 nasopharyngeal carcinoma and 7 non-tumoral inflammatory pharynx tissues using immunohistochemical methods. Patient clinical data were collected, and histological evaluation was performed by hematoxylin/eosin staining. β-catenin was detected in membrane and cytoplasm in all cases of nasopharyngeal carcinoma, regardless of histological type; in non-tumoral tissues, however, β-catenin was observed only in the membrane. As for E-cadherin expression levels, strong staining was observed in most non-tumoral tissues, but staining was only moderate in nasopharyngeal carcinoma tissues. E-cadherin expression was associated with β-catenin localization, study group, metastatic disease, and patient outcomes. Reduced levels of E-cadherin protein observed in nasopharyngeal carinoma may play an important role in invasion and metastasis. Cytoplasmic β-catenin in nasopharyngeal carcinoma may impair cell–cell adhesion, promoting invasive behavior and a metastatic tumor phenotype.

Prognostic significance of fascin-1 and E-cadherin expression in laryngeal squamous cell carcinoma

Fascin-1 and E-cadherin, both of which are related to cell motility and cell adhesiveness, are important factors in the progression and metastasis of cancers. The objective of this study was to explore the association between fascin-1 and E-cadherin expression levels with both the clinical characteristics and prognoses of patients with laryngeal squamous cell carcinoma; we did so through statistical analyses. In our study, tumor tissue samples from 150 patients with laryngeal squamous cell carcinoma were examined for fascin-1 and E-cadherin expression by immunohistochemistry. Fascin-1 expression was found to be an independent predictive factor for recurrence in patients with laryngeal squamous cell carcinoma (P = 0.021) and independently related to disease-free survival (P = 0.010). Although E-cadherin expression status was not an independent predictive factor for recurrence (P = 0.055) or disease-free survival (P = 0.063), when using subgroup analysis, the subgroup with high fascin-1 expression/low E-cadherin expression had the poorest prognosis (P = 0.000). Fascin-1 expression could be a potential prognostic predictor for patients with laryngeal squamous cell carcinoma. Simultaneous analyses of fascin-1 and E-cadherin expression could be more effective in evaluating the prognoses of patients with laryngeal squamous cell carcinoma.

The usefulness of new serum tumor markers in head and neck squamous cell carcinoma

Objective: To determine the usefulness of specific and reliable serum biomarkers to predict cervical lymph node metastasis.

Methods: A cross-sectional study of cases and controls. Thirty-nine serum samples of head and neck squamous cell carcinoma were collected from patients during neoplasm resection. Another 10 serum samples were collected from healthy individuals as a control group. Selected serum biomarkers were E-cadherin, MMP-2, MMP-9, active MMP-13, and p53 autoantibodies.

Results: We found a correlation between active MMP-13 (>685 pg/mL; ROC curve analysis 95% CI for sensitivity 79.6-99.3; specificity 49.2-95.1; positive predictive value 65-100; and negative predictive value 36-100) as well as the presence of p53 autoantibodies and lymph node metastasis. Multimarker analysis using MMP-13 and p53 autoantibodies together provided better sensitivity (76%) and specificity (100%).

Conclusions: The combined determination of active MMP-13 and p53 autoantibodies could improve diagnosis of lymphatic metastasis in head and neck squamous cell carcinoma and aid therapeutic decision making.

[Molecular alterations in nodal metastases and its primary tumors in squamous cell carcinomas of the larynx]

INTRODUCTION AND OBJECTIVES

The successive acquisition of molecular alterations determines tumour progression. During this progression, the development of nodal metastases is one of the most important prognostic factors in laryngeal squamous cell carcinomas. The aim of this study is to analyze if, in these carcinomas, the molecular alterations in the nodal metastases are different from those present in the primary tumour.

MATERIAL AND METHOD

Paired samples of primary tumour and nodal metastases from 51 patients with squamous cell carcinoma of the supraglottic larynx were studied. Using immunohistochemistry, we analyzed the expression of p53, E-cadherin, FAK, annexin A2 and HIF-1a proteins. In addition, the apoptotic index (measuring activated caspase-3) and the degree of vascularization (identified by CD34 antigen expression) were also studied.

RESULTS

A close correlation in the expression of the proteins studied was observed in the nodal metastases and the corresponding primary tumour, with the exception of HIF-1a expression and the degree of vascularization.

CONCLUSIONS

Most of the molecular alterations in the nodal metastases are already present in the primary tumour, suggesting that these alterations are early events in carcinogenesis.

Elective supraomohyoid neck dissection for oral cavity squamous cell carcinoma: Is dissection of sublevel IIB necessary?

Spinal accessory nerve (SAN) dysfunction and related shoulder disability are common consequences of supraomohyoid neck dissection (SOHND). Nerve dysfunction is usually attributed to excessive nerve traction or devascularization during clearance of the lymph nodes posterior and superior to the SAN (sublevel IIB). The need for routine dissection of this sublevel with elective neck dissection has recently been questioned. This review article discusses whether preserving sublevel IIB lymph nodes is justified in elective SOHND for patients with squamous cell carcinoma (SCC) of the oral cavity. A review of the literature was conducted on studies of sublevel IIB dissection in elective SOHND for SCC of the oral cavity. Only two studies have prospectively investigated the incidence of lymph node metastasis in patients with clinically N0 SCC of the oral cavity. Data from these two prospective pathologic and molecular analyses of neck dissection specimens, including 122 patients with N0 oral cancer, revealed 7.3% with positive neck nodes at sublevel IIB for oral cancer in general, and 12% for tongue cancer in particular. When considering the merits of preservation of sublevel IIB, the benefit of preservation of SAN function has to be weighed against potentially reduced oncologic control.

[Annexin A2 expression in head and neck squamous cell carcinoma]

OBJECTIVE

Over-expression of annexin A2 (ANXA2) has been reported in various cancers. However, no data are available on the expression of this protein in head and neck squamous cell carcinomas (HNSCC). The objective of this preliminary study is to investigate the expression of ANXA2 in these carcinomas.

MATERIAL AND METHOD

ANXA2 expression was analyzed by immunohistochemistry in paraffin-embedded sections from 9 patients with premalignant lesions and 21 patients with HNSCC.

RESULTS

All dysplastic tissues showed significantly reduced ANXA2 expression compared to normal tissue. In contrast, ANXA2 expression was observed in all but one of the tumours studied. There was a significant correlation of lower ANXA2 expression with a poorer histological differentiation, larger tumours, and nodal metastases.

CONCLUSIONS

Our data show for the first time that ANXA2 is expressed in head and neck squamous cell carcinomas and that its expression seems to be related with the degree of differentiation status of these tumours.

Neck dissection: then and now

The significance of metastatic disease in the lymph nodes of the neck as a critical independent prognostic factor in head and neck cancer has long been appreciated. Although 19th century surgeons attempted to remove involved cervical lymph nodes at the time of resection of the primary cancer, a systematic approach to en bloc removal of cervical lymph node disease, described in detail by Jawdyński in 1888 and popularized and illustrated by Crile in the early 20th century, provided consistent and more effective treatment, and forms the basis of our current techniques. During the first half of the 20th century, developments included preservation of the accessory nerve in selected cases, elective neck dissection performed in association with resection of various primary tumors, bilateral neck dissection and limited neck dissection. The greatest impetus to the status of radical neck dissection came from Martin, whose technique consisted of resection of all lymph nodes from level I-V together with the accessory nerve, internal jugular vein, sternocleidomastoid muscle and various other structures in a single block of resected tissue. Martin's technical precepts were followed until the latter part of the 20th century when modifications in technique began to find general acceptance. The first description of an effective technique of modified radical neck dissection was published in Spanish by Suárez, in 1963. This technique, which preserves important structures, such as the internal jugular vein, sternocleidomastoid muscle and accessory nerve, was refined and popularized by various authors who published their results in the English language literature during the period from 1964 through 1990 and beyond. Modified or "functional" neck dissection avoids much of the morbidity of radical neck dissection while achieving equivalent degrees of control of regional disease in properly selected cases. By the late 20th century, the concept of selective neck dissection, consisting of resection of only the nodal groups at greatest risk for metastasis from a given primary site, was studied and developed. These limited dissections are now widely employed for elective, and in properly selected cases, therapeutic treatment and staging of the neck, and have been proposed for limited cervical recurrences after various chemoradiation protocols. Prospective studies have demonstrated similar rates of neck recurrence and survival after elective selective neck dissection compared to elective modified radical neck dissection. Other modifications and factors applied to treatment of cervical lymph node disease include the use of adjuvant and neo-adjuvant radiation and chemotherapy, a revised system for classification of neck dissections, the identification of various adverse prognostic factors such as extracapsular spread and extranodal soft tissue deposits, application of sentinel lymph node biopsy to staging of the neck, the use of immunohistochemical and molecular techniques for identification of lymph node metastases not detectable by light microscopy, and the possibility of endoscopic neck dissection. The authors conclude that neck dissection, as evolved over the past century, is a fundamental tool in management of patients with head and neck cancer, but is still a work in progress.

Molecular mediators of metastasis in head and neck squamous cell carcinoma

BACKGROUND

The presence of regional metastasis in patients with head and neck squamous cell carcinoma (HNSCC) is a common and adverse event associated with poor prognosis and high mortality. Although significant improvements in standard therapies have increased the efficacy of local tumor management, the high incidence of tumor recurrence has resulted in limited improvements in overall survival rates. Understanding the molecular mechanisms that mediate HNSCC invasion and metastasis may enable identification of novel therapeutic targets for the prevention and management of tumor dissemination.

METHODS

A literature review was performed.

RESULTS

Several biologic mediators and mechanisms that have been implicated in HNSCC metastasis, such as cell adhesion molecules, proteolytic enzymes, growth factor signaling, metastasis suppressor genes, and chemokine receptors were reviewed.

CONCLUSIONS

Prevention of HNSCC metastasis is an important clinical objective that requires an increased understanding of the molecular mechanisms of tumor invasion and dissemination.

E-cadherin, MMP-2, and MMP-9 as prognostic markers in penile cancer: analysis of 125 patients

OBJECTIVES

The treatment of choice for invasive penile carcinoma is amputation and lymphadenectomy. The latter is associated with a high morbidity rate. Analysis of new prognostic factors such as E-cadherin, matrix metalloproteinase (MMP)-2, and MMP-9 may help to select candidates for lymphadenectomy.

METHODS

We assessed 125 patients with penile epidermoid carcinoma treated with amputation and bilateral lymphadenectomy. The following factors were analyzed: age, race, disease evolution time, venereal background, clinical and pathologic stage, tumor thickness, differentiation grade, venous and lymphatic embolization, koilocytosis, type of invasion, and E-cadherin, MMP-2, and MMP-9 immunoreactivity. The value of risk factors for lymph node metastases and specific survival was assessed.

RESULTS

The mean follow-up was 76.5 months. Clinical N stage (P = 0.001), tumor thickness (P = 0.027), lymphatic permeation (P < 0.001), venous embolization (P = 0.002), corpus cavernosum infiltration (P = 0.002), and low E-cadherin expression (P = 0.032) significantly correlated with the presence of metastases. Independent risk factors for metastases were lymphatic permeation (relative risk [RR] = 5.99; 95% confidence interval [CI] 2.1 to 16.9) and clinical N stage (RR = 5.5; 95% CI = 1.9 to 16.7). Lymph node metastases (RR = 57.9; 95% CI = 7.4 to 453.9), urethral infiltration (RR = 3.5; 95% CI = 1.3 to 9.2), and MMP-9 immunoreactivity (RR = 3.2; 95% CI = 1.2 to 8.3) were considered independent risk factors for disease recurrence.

CONCLUSIONS

On univariate analysis, low E-cadherin immunoreactivity was associated with a greater risk of lymph node metastases. High MMP-9 immunoreactivity was an independent risk factor for disease recurrence.

Prognostic significance of E-cadherin-catenin complex in epithelial ovarian cancer

OBJECTIVE

To clarify the prognostic role of E-cadherin and beta- and gamma-catenins, and their relation to CD44 in epithelial ovarian carcinoma.

METHODS

The expression of E-cadherin and beta- and gamma-catenins was analysed immunohistochemically in 305 primary epithelial ovarian cancers and 44 metastases, and related to CD44 expression, clinicopathological factors, and the patients' survival.

RESULTS

Reduced cell surface expression of E-cadherin, beta-catenin, and gamma-catenin was particularly frequent in serous and endometrioid histological types. Reduced cell surface expression of E-cadherin and beta-catenin was also associated with poor differentiation. Nuclear positivity of beta-catenin was associated with high CD44 expression, endometrioid histology, and local stage of the tumour, whereas nuclear gamma-catenin expression was associated with serous histology and poor differentiation. In the univariate analysis, preserved cell surface beta-catenin expression in the whole study material and nuclear expression of beta- and gamma-catenins in the subgroup of endometrioid ovarian cancers were predictors of better 10 year disease related survival. Preserved cell surface expression of E-cadherin and beta-catenin predicted favourable recurrence-free survival. These statistical significances were not retained in multivariate analysis.

CONCLUSIONS

The correlation between nuclear beta-catenin and CD44 indicates that beta-catenin may regulate the transcription of CD44 in epithelial ovarian cancer. E-cadherin-catenin complex members are associated with the prognosis of patients with epithelial ovarian cancer, but these univariate associations were not strong enough to compete for significance with the traditional clinicopathological factors.

Tumor metastasis in an orthotopic murine model of head and neck cancer: Possible role of TGF-beta 1 secreted by the tumor cells

In an orthotopic murine model of head and neck cancer, combined subcutaneous and intratumoral vaccination with recombinant vaccinia virus expressing interleukin-2 (rvv-IL-2) induced significant tumor regression early on therapy. However, its efficacy was restricted by recurrent tumor growth and loco-regional metastases. In this study, we explored the mechanism of tumor metastasis. We compared the levels of expression of a number of molecules involved in tumor metastasis, which included transforming growth factor-beta1 (TGF-beta1), E-cadherin, matrix metalloproteinases (MMPs): MT1-MMP, MMP-2, MMP-9, their tissue inhibitors (TIMPs): TIMP-1/TIMP-2, and pro-angiogenic factors CD31, VEGF-R2, and iNOS between primary and metastatic tumors by real-time RT-PCR and immunohistochemistry. We detected spontaneous lymph node and tongue metastasis. Metastasis was delayed in rvv-IL-2 treated mice. Cultured tumor cells expressed negligible amount of TGF-beta1. Untreated or metastatic tumors, on the other hand, expressed high levels of TGF-beta1 and secreted TGF-beta1 in the sera of tumor-bearing mice. Levels of TGF-beta1 in the sera suddenly jumped at the time when tumor metastasis started. In the metastatic tumors, levels of MT1-MMP, MMP-2, and MMP-9 were significantly elevated (P < 0.001), while levels of TIMP-1/TIMP-2 and E-cadherin were decreased (P < 0.001) compared to control or primary tumors. Levels of CD31, VEGF-R2, and iNOS were also significantly elevated in the metastatic lesions (P < 0.001). The concurrence of high levels of TGF-beta1 in the sera, expression of proteins involved in metastasis and initiation of metastasis suggested possible role of TGF-beta1 in on setting the metastatic cascade in this model.

The role of epidermal growth factor receptor and E-cadherin for the outcome of reduction in the overall treatment time of radiotherapy of supraglottic larynx squamous cell carcinoma

Reduction of the overall treatment time (OTT) of radiotherapy results in increased T-site control in squamous cell carcinomas of the head and neck (HNSCC). However, the response is heterogeneous and accelerated repopulation of clonogenic tumour cells during therapy may be one of the factors determining this response. The aim of the present study was to identify the influence of the epidermal growth factor receptor (EGFr) and E-cadherin for T-site control when the OTT was reduced and whether the markers add information to the histopathological grading in selecting patients for accelerated radiotherapy. A total of 209 patients from randomized DAHANCA-trials with supraglottic larynx squamous cell carcinomas treated with primary radiotherapy with different OTT of 9(1/2), 6(1/2), and 5(1/2) weeks. Available formalin-fixed paraffin embedded tumour tissues were re-evaluated for histopathological characteristics and stained for EGFr and E-cadherin. Data were correlated with patient and tumour characteristics and 5-year T-site control. EGFr and E-cadherin were not associated with patient or tumour characteristics except that EGFr correlated to carcinomas with a well to moderate histopathological feature. Tumours with high EGFr or low E-cadherin did benefit from reduced OTT, and the combination of the two (high EGFr and low E-cadherin) had the most significant acceleration of treatment effect, compared with tumours with other combinations of EGFr and E-cadherin expression. Tumours with high expression of EGFr and low expression of E-cadherin showed the most significant increase in T-site control when the overall treatment time of radiotherapy was reduced, and the markers may be useful for selecting patients who will benefit from accelerated radiotherapy.

E-cadherin is a selective and strongly dominant prognostic factor in squamous cell carcinoma: a comparison of E-cadherin with desmosomal components

E-cadherin-mediated and desmosomal cell-cell adhesion have been implicated in the suppression of invasive and metastatic behavior of squamous cell carcinomas. Whether the adhaerens junction represented by E-cadherin and the desmosomes interplay or have distinct and separate roles in squamous cell cancer progression is still unclear. We have studied a cohort of 200 primary tumors and 56 lymph node metastases from different anatomic sites of the head and neck region for changes in synthesis of E-cadherin, desmoplakin and desmoglein by immunohistochemistry (IHC). Selected cases were studied by indirect immunofluorescence (IIF) and electron microscopy (EM). Only frozen sections were evaluated since they gave stronger and reproducible staining results. IHC data obtained were compared to clinical parameters. While some reduction in immunostaining was found in virtually all invasive tumors, at least partial expression, including that of E-cadherin, persisted in most late stage tumors and in lymph node metastases. Reduced desmosomal staining correlated with desmosomes reduced in numbers, size or in structural defects by EM analysis. By univariate analysis, reduction in synthesis of both E-cadherin and the desmosomal components that were generally linked (i.e., they showed positive rank correlations) were significantly associated with clinical parameters including overall and disease-free survival. However, by multivariate analysis including a Cox proportional hazards regression model (backward selection), the desmosomal components were not significant as independent prognostic factors. By contrast, E-cadherin was strongly associated with patient prognosis. In line with the highly significant association of reduced E-cadherin synthesis with an increased relative risk of follow up events, i.e., regional lymph node (p = 0.0007) and distant metastasis (p < 0.0001), as well as local recurrences (p < 0.0001), the prognostic strength of E-cadherin was independent of and stronger than histological grading, N stage, tumor site, and even stronger than the TNM stage. Based on these results, evaluation of E-cadherin in squamous cell carcinomas by immunostaining is recommended as a significant prognostic marker.

Loss of E-cadherin and p27 expression is associated with head and neck squamous tumorigenesis

BACKGROUND

In neoplastic head and neck lesions, it has been found that the loss or reduction in E-cadherin expression is a late event and is associated with invasion. Low p27 levels have been associated with a poor prognosis in many different tumors, including laryngeal carcinoma. The authors investigated p27 and E-cadherin protein expression in the early stages of head and neck tumorigenesis and evaluated their predictive roles individually and in association with carcinogenesis.

METHODS

Tissue biopsies from 46 patients who were participants in 3 chemoprevention trials were analyzed for E-cadherin expression, and 40 samples were analyzed for p27 expression using immunohistochemistry.

RESULTS

The data suggested that loss of both E-cadherin expression and p27 expression occurred early during the preneoplastic steps of head and neck carcinogenesis, and loss of p27 protein expression alone (P=0.02) and in combination with loss of E-cadherin expression (P=0.04) was a significant predictor of the risk for head and neck carcinoma.

CONCLUSIONS

The loss of p27 expression may be useful in the construction of a risk model for head and neck carcinogenesis and may represent a potential target for chemopreventive interventions. Longer follow-up of the high percentage of low-risk preneoplastic lesions in the current study and validation in a larger sample size may be required to establish the predictive role of these abnormalities.

Expression of integrins and E-cadherin in squamous cell carcinomas of the head and neck

Integrins and cadherins are cell adhesion molecules suggested to play an important role in malignant progression and tumour differentiation. Our aim was to characterise the pattern of expression and the relations between integrin beta1, beta4, beta6 and E-cadherin and the different histopathological features important when judging tumour differentiation, using a well-defined scoring system. Formalin-fixed paraffin-embedded pre-irradiation biopsies from 85 patients with head and neck squamous cell carcinomas (HNSCC) were stained and evaluated for the expression of integrin beta1, beta4 and beta6 and E-cadherin. The integrins were upregulated in carcinomas compared to the adjacent mucosa and E-cadherin was downregulated. However, differences were found within the tumour: Expression of E-cadherin was lost and the three integrins were upregulated at the tumour borders, compared to central parts of the tumour biopsy. Expression of the integrins did not correlate with tumour or histopathological parameters, whereas expression of E-cadherin was correlated with high degree of keratinisation, high nuclear maturation and few mitoses - factors that characterise well-differentiated carcinomas -and E-cadherin can therefore be considered as a marker of differentiation. Furthermore, loss of adhesion expressed by low E-cadherin and integrin beta4 correlated with the presence of nodal metastases at the time of diagnosis.

Staging of the neck in patients with head and neck squamous cell cancer: Imaging techniques and biomarkers

Regional metastasis is an important factor in the treatment and prognosis of head and neck cancer patients. Current treatment strategies rely on staging based on the still limited accuracy of imaging techniques to detect regional metastases. If more certainty about the nodal status could be attained, treatment strategies concerning the neck could be better adjusted to the individual patient. The continuing improvement of established imaging techniques and the introduction of new imaging modalities will add to better staging. Moreover, the additional use of biomarkers studied on a protein, RNA or DNA level may provide even better information about the chance of occult nodal metastasis in head and neck cancer patients.

Recent progress in predictive biomarkers for metastatic recurrence of human hepatocellular carcinoma: a review of the literature

Molecular markers (biomarkers) for hepatocellular carcinoma (HCC) metastasis and recurrence could provide additional information to that gained from traditional histopathological features. A large number of biomarkers have been shown to have potential predictive significance. One important aspect of this is to detect the transcripts of tumor-associated antigens (such as AFP, MAGEs, and CK19), which are proposed as predictive markers of HCC cells disseminated into the circulation and for metastatic recurrence. Another important aspect is to analyze the molecular markers for cellular malignancy phenotype, including DNA ploidy, cellular proliferation index, cell cycle regulators, oncogenes, and tumor suppressors (especially p53 gene), as well as telomerase activity. Molecular factors involved in the process of HCC invasion and metastasis, including adhesion molecules (E-cadherin, catenins, ICAM-1, laminin-5, CD44 variants, osteopontin), proteinases responsible for the degradation of extracellular matrix (MMPs, uPA system), as well as angiogenesis regulators (such as VEGF, intratumor MVD), have also been shown to be potential predictors for HCC metastatic recurrence and clinical outcomes. One important new trend is to widely delineate biomarkers with genomic and proteomic expression with reference to predicting metastatic recurrence, molecular diagnosis, and classification, which has been drawing more attention recently. Body fluid (particularly blood and urine) testing for biomarkers is easily accessible and more useful in clinical patients. The prognostic significance of circulating DNA in plasma or serum and its genetic alterations is another important direction. More attention should be paid to these areas in the future. As understanding of tumor biology deepens, more and more new biomarkers with high sensitivity and specificity for HCC metastatic recurrence could be found and routinely used in clinical assays. However, the combination of the pathological features and some of the biomarkers mentioned above seems to be more practical up to now.

Expression of E-cadherin, CD44s, and CD44v6 in laryngeal and pharyngeal carcinomas

OBJECTIVE

Tumors arising from different sites of the head and neck area have very different clinical behavior. Loss or reduction of expression of adhesion molecules has been assumed to play a critical role in the development of head and neck carcinomas. The aim of this study is to determine if there are differences in the expression of adhesion molecules E-cadherin, CD44s, and CD44v6 in pharyngeal and laryngeal squamous-cell carcinomas.

MATERIALS AND METHODS

E-cadherin, CD44s, and CD44v6 expression was determined by immunohistochemistry in paraffin-embedded tissue specimens from 72 patients with squamous-cell carcinoma, 37 of the pharynx and 35 of the larynx.

RESULTS

Expression of CD44s was significantly lower in pharyngeal than in laryngeal tumors (P =.01). No differences in the expression of E-cadherin and CD44v6 were observed between these sites.

CONCLUSIONS

These data suggest that there are some differences at molecular level between the different subsites of head and neck cancer.

Promoter methylation regulates cadherin switching in squamous cell carcinoma

Cadherins are cell adhesion molecules that modulate the epithelial phenotype and regulate tumor invasion. To identify the role of promoter methylation in regulating E-cadherin expression and in the "switching" of cadherins in oral squamous cell carcinoma (SCC), we studied 14 cell lines for cadherin expression. Immunoblotting revealed that only two (HOC-313 and HA-376) showed strong up-regulation of N-cadherin, and neither expressed E-cadherin. These results were confirmed by PCR. Furthermore, analysis of genomic DNA showed that the lack of E-cadherin expression in the two cell lines was not due to gene deletion. In both cell lines, methylation-specific PCR indicated extensive methylation of the 5' CpG island in the E-cadherin promoter. After treatment with a DNA methylation inhibitor (5-Aza-2-deoxycytidine), both immunoblotting and immunofluorescence staining showed that HA-376 cells newly expressed E-cadherin with a parallel decrease in their N-cadherin expression. Multiplex RT-PCR demonstrated that the down-regulation of N-cadherin mRNA was coordinately regulated with E-cadherin expression. Thus, methylation of the 5' CpG island in the E-cadherin promoter induces reciprocal expression of E- and N-cadherins in oral SCC by an unknown mechanism that appears to be mediated at the level of N-cadherin gene expression. These events may play an important role in the regulation of tumor cell mobility and invasion.

Expresión de las anexinas a1 y a2 en la mucosa del tracto aerodigestivo superior

INTRODUCTION

Annexins A1 and A2 have been related with the maintenance of tissue integrity. They have been identified in a wide variety of tissues, but little is known regarding their expression in upper the aerodigestive tract. The aim of this work is to describe the expression of these proteins in the mucosa of the upper aerodigestive tract.

MATERIAL AND METHODS

Tissue samples from respiratory (nasal and laryngeal) and digestive (oral and pharyngeal) mucosa from non-oncological patients were studied. Annexin A1 and A2 expression was determined by immunohistochemistry.

RESULTS

Both annexins were expressed in the ciliated and in the stratified non-keratinized epithelia, but with a different pattern; ANXA1 was expressed in the more differentiated cells whereas ANXA2 was expressed in the less differentiated ones (with the exception of the cilia of ciliated cells).

CONCLUSION

Although annexins A1 and A2 are structurally and philogenetically related its expression pattern in the upper aerodigestive tract suggests that they have different functions.